The development of efficient acetone gas sensors is essential for the real-time monitoring of acetone gases in the environment. Here, CuO nanowires embedded with Au nanoparticles (NPs) with defined size, structure, and physicochemical properties are fabricated by a wet chemical method and are found to show enhanced acetone gas sensing behavior. The precise and controllable loading of Au NPs in CuO nanowires plays a critical role in modulating the acetone gas sensing behavior. The Au/CuO-nanowire-based sensors exhibit higher response rate, faster response/recovery, and better long-term stability than the pure CuO nanowires owing to the decrease in the width of the hole accumulation layer (HAL), larger specific surface area, and more active sites for gas diffusion. Our present work may have potential application in the real-time monitoring of gases in an actual environment owing to its high response rate, ultrafast response/recovery time and long-term stability.